The present invention relates to apparatus for treating surfaces, particularly to apparatus for polishing floor surfaces, and specifically to unique and novel floor burnishing machines.
A popular method of creating a xe2x80x9cglossxe2x80x9d shine on finished tile flooring is after wet-scrubbing the floor, burnishing the floor with a machine that has a disc-shaped polishing pad rotated at a high RPM. The polishing pad removes any small imperfections and scuff marks in the finish, giving the floor a xe2x80x9cwet-lookxe2x80x9d gloss. An added benefit of burnishing is that the finish becomes xe2x80x9cwork-hardenedxe2x80x9d, which results in a more durable, usable surface.
Current burnishing machines are made in three different powered configurations: cord powered through wall outlets, battery powered through deep cycle batteries carried on board, and internal combustion (IC) powered using propane fuel rather than gasoline. Each type of machine has it""s own unique market. Cord machines are used in confined areas. Since the available power is rather limited, cord machines produce the least gloss rise of the three categories. Battery powered machines are used where areas are larger, emission requirements are more rigid, and higher gloss is required in comparison to a cord machine. The available power is greater than the cord machine, but the machine weight is greater due to the batteries on board, and the run time to discharge the batteries is a limited factor for productivity. The walk-behind propane machines have the greatest power available due to the IC engine, the run time is unlimited due to the replaceable propane tanks, and the resulting performance is the greatest of the three machines. Because of the greater performance, the machine is usually operated at a higher rate of travel speed than the other machines, which results in a higher productivity rate.
The propane machine is therefore the machine of choice for many contract cleaners and retail stores for it""s high gloss shine and high productivity. The one major drawback, however, is that the machine, due to it""s IC engine running in a confined building, creates potentially hazardous emissions in the air.
Recognizing the safety hazard associated with internal combustion engine powered machines, a need exists for a battery operated machine which equals the propane machine in gloss performance, as well as providing higher productivity, all without the emissions hazards. Also, it is desirable that the operator rides on the machine so that the battery operated burnishing machine can travel faster than a walk-behind propane machine, and the operator will not tire during extended operating periods.
The present invention solves these needs and other problems in the field of surface treating apparatus by providing, in the preferred form, a battery box mounted in the chassis as low as possible with the bottom of the battery box defining a space with the surface which is free of obstruction so that the center of gravity is lowered and the stability of the apparatus is increased.
In another aspect of the present invention, a battery box for holding the apparatus batteries can be removed and inserted into the apparatus chassis in a horizontal movement direction while supported by the bottom of the battery box, with the battery box in the most preferred form being prevented from moving in the horizontal movement direction in a lowered position while being allowed to move in the horizontal movement direction in a raised position.
In other aspects of the present invention, a steering column is pivotably connected to a pillar of the chassis of a surface treating apparatus and rotatably mounts an upper steering shaft which is rotatably and pivotably connected to a lower steering shaft rotatably mounted in the pillar, with the rear wheels of the surface treating apparatus being rotatably connected to the lower steering shaft for being turned by the manual rotation of the upper steering shaft. In the most preferred form, the steering column can be locked in one of a plurality of pivotable positions relative to the pillar.
In still other aspects of the present invention, the surface treating member is raised, lowered, and allowed to float relative to the surface by providing a housing which is restrained on a nut threadable on the rotatable threaded shaft of an actuator but which is allowed axial movement relative to the nut for a distance while being biased away from the nut, with the housing being pivotably mounted to a linkage pivotably mounted to the apparatus chassis and the surface treating member and with the actuator being pivotably mounted to the apparatus chassis.
In further aspects of the present invention, the pressure which a treating member engages the surface is controlled in response to the current level of the electric motor which rotates the treating member, with the treating member being moved towards the surface if the current level is below a predetermined range and being moved away from the surface if the current level is above a predetermined range.
In most preferred aspects of the present invention, the current of an electrical device and particularly the electric motor which rotates the surface treating member is measured by monitoring the voltage at the ends of the negative supply lead cable (and in the most preferred form the temperature of the cable) rather than a conventional shunt in series with the electric device.
It is thus an object of the present invention to provide a novel apparatus for treating surfaces.
It is further an object of the present invention to provide such a novel surface treating apparatus having extended operation without potentially hazardous emissions.
It is further an object of the present invention to provide such a novel surface treating apparatus having easily interchangeable battery packs for extended operation.
It is further an object of the present invention to provide such a novel surface treating apparatus upon which the operator rides.
It is further an object of the present invention to provide such a novel surface treating apparatus which travels faster than conventional walk-behind apparatus.
It is further an object of the present invention to provide such a novel surface treating apparatus which is battery operated but provides burnishing performance equaling that of propane powered apparatus.
It is further an object of the present invention to provide such a novel surface treating apparatus providing higher productivity.
It is further an object of the present invention to provide such a novel surface treating apparatus having a unique floating linkage for the operating head.
It is further an object of the present invention to provide such a novel surface treating apparatus having a treating member engaging the surface responsive to the current level of the electric motor which rotates the treating member.
It is further an object of the present invention to provide such a novel surface treating apparatus which monitors the current level through the electric motor by monitoring the voltage drop through the negative supply lead cable and without a conventional shunt.
These and further objects and advantages of the present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings.